How do you select the right processor?

I think that asking an experienced professional engineer how they choose the right processor is about the same as asking a cancer specialist how to choose the right treatment !!

It's like pretty much any professional skill - you need some aptitude and at least 10,000 hours of practice - a wiki page is no substitute.

Having said that there are some very general comments:

You should consider the total project cost (for low to medium volumes this often means that the cost of the processor is unimportant). This will enable you to set a budget for choosing the processor. (This step is frequently informal and that's fine for many projects but if you have to think about long term availability, safety critical, large volumes then perhaps you should set a formal budget.)

You need to make a list of "must haves" - and in real life these range from very technical (eg on chip 16 bit ADC) to the near political (eg must complete the job in 2 weeks and the only available engineer knows processor X really well .......).

If your "must have" requirements give you a short list it may be quite easy to pick the part - more likely there will be thousands of parts or none at all that meet your initial requirements (this will depend on the skill with which the requirements were defined).

So I think I have shown that choosing a processor is not a simple matter of ticking some boxes.

To address your specific points:

In low volumes familiarity with processor and/or tools may be a very significant cost factor but my personal opinion is that it is often overplayed.

It is usually (but there will be exceptions) a bad idea to change parts between prototyping and manufacture.

The value of future proofing is totally project dependent - if you are building a one off piece of test gear there is no value at all - if there is a planned 'family' of products it may be the key to commercial viability.

Hi Michael,

I agree with all of your points, and in essence that's why I'm interested in posting this discussion. As you say, there is a wealth of factors which might determine how you select a processor, what I am curious about is can a community of engineers contribute to creating any sort of guide. Is it possible to collect, distil and fuse the knowledge and experience of many into something usable and valuable on this subject?

The comment about the wiki document (by which I mean an e14 document which would be open to all to collaborate on, not a wikipedia document) is just an idea of how anything useful gained from this discussion might eventually be displayed. My hope is that this discussion can result in some general principles which might at least allow a user to arrive at some conclusion, be it architecture, supplier or product family.

There are 1000s of people a day now visiting this site from all over the world, and the result of this discussion will be as much about the potential power for collaboration as it is about processor selection. I hope that many, like yourself will contribute their knowledge and experience to explore what's possible through a site like this.

Let me be open and say that may personal experience in this area is limited, but it is a question I have asked in the past and struggled with myself once or twice, never with a answer to which I am wholly satisfied.

Thanks again for posting

Hi,

I don't think that I am so experienced but I suggest you,if you use a pic MCU,to download

Microchip Advanced Part Selector (MAPS) from Microchip site.

It's very useful tool

Regards

Chris

Hi,

I don't think that I am so experienced but I suggest you,if you use a pic MCU,to download

Microchip Advanced Part Selector (MAPS) from Microchip site.

It's very useful tool

Regards

Chris